Process of manufacturing pronged rivets



(No Model!) M. BRAY.

PROCESS OF MANUFAOTURING PBONGED RIVETS.

No. 402,650. Patented May 7, 1889.

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wma5i.-4MM by M Z 1 ,Jillorney.

UNITED :STATEs PATENT OFFICE.-

MELLEN BRAY, OF NEWTON, MASSACHUSETTS.

PROCESS OF-MANUFACTURING PRONGED RIVETS.

SPECIFICATION forming part of Letters Patent No. 402,650, dated May 7,1889.

Application filed January 3, 1889- Serial No. 295,374. (No model.) I

To all whom. it may concern.-

'Be it known that I, MELLEN BRAY, of N ewton, in the county of Middlesexand State ofspecification.

My invention relates to the manufacture of rivets having a plurality ofsecuring-prongs from solid wire; and it consists in an improved methodor process of forming such rivets, which will be readily understood byreference to the description of the accompanying drawings, illustratingsaid process, and to the claim to be hereinafter given.

I11 the drawings illustrating my invention, Figures 1 and 2 arerespectively a plan and a sectional elevation of a solid cylindricalrivet having a countersunk end with its outer corner beveled, andillustrating thefirst step in the production of a pronged rivet from ashort cylinder of wire. Figs. 3 and 4 are respectively a plan and anelevation of the same rivet or blank as it-appears after the sides ofthe shank have been flattened by the second operation. Fig. 5-is anelevation of the same viewed in a direction at right angles to Fig. 4.Figs. 6 and? are respectively a plan and an elevation of the improvedrivet produced by my improved process.

The rivet shown in Figs. 6 and 7 forms the subject-matter of anotherapplication of mine of even date herewith, in which the process ofproducing it is described but not claimed.

In the manufacture of pronged rivets from solid wire, as heretoforepracticed, a solid rivet having a cylindrical shank has been firstproduced, and then the shank has been divided into two prongs by cuttingaway the central portion of the stock by means of revolving cutters ormilling-tools, so called. This is necessarily a slow and expensiveoperation, and has therefore proved impractical. Attempts have been madeto cut out the central portion of the stock of the cylindrical solidshank by means of apunch and die, but without practical success, for thereason that the breaking.

end of the punch or male die had to be made to fit the rounded side ofthe cylindrical shank, and the dies in consequence were, constantly Toobviate this difficulty and render it practical to use male and femaledies to remove the central portion of the stock from the shank of thesolid shank of the rivet-blank is the object of my present invention;and to this end I first form the solid rivet, as shown in Figs. 1 and 2,from a short section of solid wire as the first step in my improvedprocess. I then subject the shank b of said solid rivet to the action ofpressure-dies to flatten two opposing sides thereof, as shown at c o inFigs.

3 and 4, said flattened surfaces 0 0 being formed of a width at leastequal to the desired width 7 between the two prongs d d of the finishedrivet shown in Figs. 6 and 7. I then place the flattened shank betweensuitably-shaped male and female dies the ends or bearing-surfaces ofwhich are planes, and punch out the central portion of the stock,leaving the shank of the rivet in the form of two prongs, substantiallyas shown in Figs. 6 and 7.

The flattened sides may be slightly inclined to each other, as shown inFig. 5, or they may be parallel, if preferred, without affecting theprinciples of my invention.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-

The process of forming pronged rivets from sections of solid wire, whichconsists in first forming a head upon a short section of said wire, thensubjecting the shank of the solid rivet thus formed to pressure toflatten two opposing sides thereof, and then punching out the centralportion of the stock of said fiat toned shank by subjecting it to theaction of male and female dies.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 24th day of Decem ber, A.D. 1888.

MELLEN BRAY.

\Vitnesses:

WALTER E. LOMBARD, N. C. LOMBARD.

